Intra-operative ultrasonography as a routine screening procedure in biliary surgery.

Intra-operative cholangiography and ultrasonography were compared in screening for unsuspected common bile duct stones. In 57 consecutive patients both procedures were performed, and in 60 only ultrasonography was used. Although the study was conducted during the initial self-teaching period (regarding ultrasonography) the results show an advantage of this relatively new diagnostic technique. The false positive rate was lower and consequently the predictive value of a positive test was higher for intraoperative ultrasonography. The main benefit would thus be a lower rate of negative common bile duct explorations. Our early results suggest that the general surgeon would need only a short adaptation period to this imaging modality, which would seem to be a valuable alternative to intra-operative cholangiography.